Association of Modic change types and their short tau inversion recovery signals with clinical characteristics- a cross sectional study of chronic low back pain patients in the AIM-study

Table 2 Background characteristics

	N	Type 1 MCs	Type 2 MCs	P-value
Age, mean ± SD	180	45.3 ± 9.2	44.4 ± 8.6	0.54
Female, n (%)	180	70 (59%)	35 (56%)	0.71
Body mass index (BMI), mean ± SD	178	25.6 ± 4.0	26.9 ± 4.1	0.046
Smoking, n (%)	178	31 (27%)	15 (24%)	0.71
Educational level, n (%)	177			0.41
Primary school (9 years)		12 (10%)	7 (11%)
High school (12 years)		48 (42%)	30 (48%)
College/University < 4 year		28 (24%)	17 (27%)
College/University ≥4 year		27 (23%)	8 (13%)
Comorbidities, n (%)
Diabetes	180	2 (2%)	1 (2%)	0.97
Psychiatric disease	180	5 (4%)	3 (5%)	0.85
Obesity	180	19 (16%)	10 (16%)	0.98
RMDQ, mean ± SD	178	12.6 ± 4.0	13.0 ± 4.6	0.58
Low back pain intensity, 0–10 NRS, mean ± SD	177	6.4 ± 1.2	6.2 ± 1.6	0.44
Leg pain intensity, 0–10 NRS, mean ± SD	179	3.0 ± 2.6	3.6 ± 2.5	0.17
EQ-5D, median (IQR)	179	0.60 (0.46–0.68)	0.56 (0.36–0.67)	0.28^a
Emotional distress (HSCL −25) ≥1.75, n (%)	179	26 (22%)	21 (34%)	0.09
FABQ physical activity, 0–42, mean ± SD	179	12.2 ± 6.0	11.4 ± 5.7	0.39
FABQ work, 0–42, mean ± SD	176	17.0 ± 11.8	19.8 ± 11.9	0.15
Duration of low back pain, years median (IQR)	177	3 (1.7–6.3)	3.3 (1.3–6)	0.47^a
Physical workload, n (%)	151			0.14
Job requires walking and lifting a lot or physically heavy work		28 (28%)	20 (39%)
Level with Modic change, n (%)
L1/L2	180	0	0	–
L2/L3	180	4 (3%)	0	0.14
L3/L4	180	7 (6%)	5 (8%)	0.59
L4/L5	180	52 (44%)	25 (40%)	0.63
L5/S1	180	84 (71%)	48 (77%)	0.37
Concomitant medication, n (%)
Analgesics, any ^b		77 (65%)	46 (74%)	0.22
Opioids (tramadol or codeine)		28 (24%)	27 (44%)	0.006

RMDQ Roland-Morris Disability Questionnaire. Pain and disability measure, ranges from 0 to 24, with a lower score indicating less severe pain and disability [46, 47]
NRS Numerical Rating Scale. A mean of three NRS scores; current pain, worst pain within the last 2 weeks, and usual/mean pain within the last 2 weeks. Used for low back pain intensity [33] and leg pain intensity [35]
EQ-5D Health related quality of life scores (EuroQoL -5D5L, version 2.0) [61]. Measured on 5 dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression, with a score 1–5 on each dimension. These values are converted to a single summary index by applying a ‘crosswalk value set’ for UK, giving a score from −0.59 to 1.0 (higher scores indicate a higher quality of life)
HSCL Hopkins Symptom Checklist–25 [31]. A measure of emotional distress
FABQ Fear-avoidance beliefs Questionnaire [32]
IQR Interquartile range (25th percentile - 75th percentile)
^aNon-parametric test
^bIncluding paracetamol/acetaminophen, NSAIDs, phenazone, acetylsalicylic acid and opioids (tramadol or codeine)

ISSN: 1471-2474